I know guys that have made their own cranks and rods to hop these little old Hondas up. Maybe I'll try and get some pictures of some of the parts they have laying around.
I just watched/ helped a friend put a digital ignition on a 1976 Norton Atlas on Sunday. I've put kits on Kohler and Briggs engines - super simple. I couldn't help thinking about making a kit for my own old Hondas.